A 190 ky record of lithogenic grain-size on the Namibian slope: Forging a tight link between past wind-strength and coastal upwelling dynamics

Variations in the coarse-grained dust diameter are closely correlated with SST changes. Past SSTs records from the Namibian upper slope have been previously hypothesized as reflecting upwelling intensity combined with occasional injection of warm-water from the Angola Dome. We challenge this view in considering that past long-term SSTs variations are primarily induced by the wind-strength and witness coastal upwelling intensity. Early MIS 6 is the only period with evidences of warm, poleward water intrusion at the core site. The windiest conditions occurred during isotopic stages 3 and 4. The wind-strength proxy defined in this study can be used confidently as an independent proxy for past upwelling intensity over the last two climatic cycles.